Solar heating blocks

ABSTRACT

A solar heating block, designed for use in assembling solar heating panels in the walls of buildings, has a first compartment and a second compartment within its interior volume. The first compartment contains a translucent insulating material, such as an aerogel. The second compartment, which is inward of the solar heating block from the first compartment, contains a heat-absorbing material. The translucent insulating material allows light to be transmitted through the solar heating block, but reduces heat loss to the exterior of the building from the heat-absorbing material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/226,078 to Wendell B. COLSON for the same title as the presentapplication, filed on Oct. 6, 2008, which is the U.S. National Stage ofinternational Application No. PCT/US2007/008616, filed Apr. 5, 2007,which includes a claim for priority based on U.S. Patent ApplicationSer. No. 60/790,464, filed Apr. 7, 2006, the entire disclosure of eachof which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of passive solar energyheating units which may be installed in building walls in the manner ofwindows.

2. Description of the Related Art

Passive solar heating units of the subject type are known in the art.For example, U.S. Pat. No. 4,532,917 to Taff et al. shows a modularpassive solar energy heating unit for heating an enclosed space. Theunit employs phase change heat storage material, which is opticallytransparent to visible light when in a high-stored-energy liquid state,enabling a viewer to see through clearly, and which is translucent milkywhite when in a low-stored-energy solid state for providing pleasantillumination to the enclosed space when first illuminated by sunlight inthe morning.

An undesirable characteristic of this and other such modular passivesolar energy heating units of the prior art is their tendency to radiatetoo much of the heat stored during the daylight hours back outside thebuilding at night. As a consequence, less of the stored heat remainsavailable to heat the building at night. In addition, the heat that doesremain to be transmitted into the building does so too quickly, with theresult that its benefit is felt for only a relatively short time.

The present invention provides a solution to these and other problems ofthe prior art.

SUMMARY OF THE INVENTION

Accordingly, the present invention is a solar heating block which isdesigned for assembling a solar heating panel in the wall of a building.The solar heating block is an insulating, infrared-absorbing,light-diffusing block and has a top, a bottom, a first side, a secondside, a first face and a second face. The solar heating block has aninterior volume which includes a first compartment and a secondcompartment.

The first compartment is formed in part by the first face, which isdisposed in use on the outside of the building. The second compartmentis between the first compartment and the second face. The firstcompartment contains a translucent insulating material, such as anaerogel. The second compartment contains a heat-absorbing material, suchas water.

In an alternative embodiment, the solar heating block has an interiorvolume including first, second and third compartments. The firstcompartment is formed in part by the first face, the second compartmentis formed in part by the second face and the third compartment isbetween the first and second compartments. The first compartmentcontains a translucent insulating material, such as an aerogel. Thethird compartment contains a heat-absorbing material, such as water. Thesecond compartment also contains a heat absorbing material, such aswater, where the solar heating block is intended for use in a solarheating panel on a side of a building exposed to the rays of the sun inthe winter, specifically, the south side of a building in the northernhemisphere or the north side of a building in the southern hemisphere.On the other hand, the second compartment also contains a translucentinsulating material, such as an aerogel, where the solar heating blockis intended for use in a solar heating panel on the east or west side ofa building.

In a variation of this alternative embodiment, a block intended for usein a panel substantially unexposed to direct solar radiation at any timeof the year, namely, a panel on the north side of a building in thenorthern hemisphere or on the south side of a building in the southernhemisphere, the first and second compartments contain a translucentinsulating material, such as an aerogel, while the third compartment mayeither be empty or filled with a translucent insulating material, suchas an aerogel.

The present invention will now be described in more complete detail,with frequent reference being made to the figures identified below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a solar heating panel;

FIG. 2 is a vertical sectional view taken as indicated in FIG. 1;

FIG. 3 is horizontal sectional view taken as indicated in FIG. 1;

FIG. 4 is a perspective view of the left side of the solar heating blockincluded in the panel of FIG. 1;

FIG. 5 is a perspective view of the right side of the solar heatingblock;

FIG. 6 is an exploded view of the left side of the solar heating block;

FIG. 7 is a vertical cross-sectional view of an alternative embodimentof the solar heating block;

FIG. 8 is a vertical cross-sectional view of still another alternativeembodiment of the solar heating block;

FIG. 9 is a vertical cross-sectional view taken through two verticallystacked solar heating blocks of FIG. 8;

FIG. 10 is a perspective view of the top surfaces of two adjacent solarheating blocks of FIG. 8;

FIG. 11 is a perspective view of alternative top surfaces of twoadjacent solar heating blocks of FIG. 8;

FIG. 12 is a vertical cross-sectional view through a further embodimentof the solar heating block;

FIG. 13 is a horizontal cross-sectional view through the solar heatingblock shown in FIG. 12;

FIG. 14 is a perspective view of honeycomb material which may be used inthe solar heating blocks of the present invention;

FIG. 15 is a vertical cross-sectional view of yet another embodiment ofthe solar heating block;

FIG. 16 is a vertical cross-sectional view of still another embodimentof the solar heating block;

FIG. 17 is a cross-sectional view through a portion of the solar heatingblock of FIG. 8 prior to assembly;

FIG. 18 is a cross-sectional view through the portion of the solarheating block shown in FIG. 17 following assembly;

FIG. 19 is a perspective view of a portion of the solar heating panel ofFIG. 1 and a fabric tile;

FIG. 20A is a plan view of an alternate fabric tile; and

FIG. 20B is a side view of the solar heating panel of FIG. 1 showing thefabric tile of FIG. 20A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to these figures, FIG. 1 is an elevational view of a solarheating panel 10 assembled from the solar heating blocks 20 of thepresent invention. Such a panel 10 would preferably be installed on thesouth side of a building (in the northern hemisphere) in order toreceive maximum exposure to the winter sun, but would be at least partlyshaded in the summertime by eaves or an overhang. The view shown in FIG.1 is one of the panel 10 from inside the building, where the panel 10takes the place of a window having southern exposure. The view fromoutside the building, at least in its overall appearance, would be verymuch the same as that presented in FIG. 1.

As will be demonstrated below, the solar heating blocks 20 interlockwith one another to provide some structural integrity to the panel 10 asa whole. In addition, the panel 10 is mounted within a frame 22 toensure a sound connection to the wall 24. While a frame is preferred, itis conceivable that the structure could be mounted into a wall without aframe.

As shown in FIG. 1, the solar heating panel 10 is an array of solarheating blocks 20 which is six blocks high and eight blocks wide. Ofcourse, it should be understood by the reader that the present inventionis not limited to arrays of these particular dimensions, and thatrectangular or square arrays of other dimensions are equally possible.Moreover, with appropriate framing, arrays of other shapes couldalternatively be constructed.

FIG. 2 is a vertical section through one of the solar heating blocks 20of panel 10, and partly showing the block 20 immediately thereabove,taken as indicated in FIG. 1. The solar heating block 20 comprises ablock body 26 having a first block body half 28 and a second block bodyhalf 30. The block body halves 28, 30 are molded from clear ortranslucent plastic, such as an acrylic plastic, and heat-welded orsealed together to produce a watertight connection.

On the left-hand side of the block 20 in FIG. 2, that is, the side ofthe block 20 on the outside of the building, is a lens 32, which is alsomolded from clear or translucent plastic, such as an acrylic plastic orother material having high solar transmission. The lens 32, havingapproximately the same height and width dimensions as the block 20, isheat-welded or sealed to face 34 of the first block body half 28 atnotch 36 which runs around the perimeter thereof. The lens 32 is about1.0 inch deep, and provides a volume that thick and of the height andwidth dimensions of the block body 26 outwardly of face 34 for atranslucent insulating material 38.

The purpose of translucent insulating material 38 is to prevent heatstored in the solar heating block 20 during; the daylight hours fromradiating outward during the nighttime hours. In addition, thetranslucent insulating material 38 allows solar radiation from outsidethe building to pass through the solar heating blocks 20 to providenatural illumination to the interior of the building and to heat thematerial within the block body halves 28, 30.

The translucent insulating material 38 of choice is aerogel, a uniqueform of highly porous non-hazardous silica having a lattice network ofglass strands with very small pores. The solids content of aerogel isextremely low (5% solid, 95% air). Aerogel is recognized to be one ofthe most lightweight and best insulating solids in the world. An aerogelhighly suited for the practice of the present invention is availablefrom Cabot Corporation of Billerica, Mass. under the name NANOGEL®.These aerogels are produced in a method which renders them hydrophobicwith the result that they repel water which otherwise tends to degradeits component particles, which are generally in a size range from 0.5 mmto 4.0 mm.

The block body 26, itself is filled with water 40, except for a smallvolume 42 at the top to allow for expansion. Three inches of pure, orclear, water absorbs about an estimated 50% of the solar infraredradiation passing through the block body 26 which generally provides awater thickness in a range from 3.0 to 6.0 inches. Several means areavailable for increasing this percentage. For example, the water may bedyed with a variety of coloring agents used for this purpose to increasethe estimated absorption to the range of 70% to 85%. Alternatively, adispersion agent may be used to color the water white or some other hue.The water may also include antifreeze and antimicrobial agents. Forexample, the water may include table salt (sodium chloride) or calciumchloride, which function both as antifreeze and antimicrobial agents. Inaddition, distilled water may be used to minimize the mineral andmicrobial content of the water being used to fill the block body 26.Finally, by filling the block body 26 with hot water, or with water thathas been previously been deaerated or degassed, the formation of bubbleson the inner surface of the block body 26 and the amount of air or gasin small volume 42 at the top of the block body 26 may be kept to aminimum.

The water 40, with or without a coloring agent, could be placed into theform of a gel through the addition of a small amount of a gelling agent,such as methylcellulose. The benefits of the gelling agent are that itprevents a spill should the block body 26 crack or break, and itinhibits convective flow within the block body 26. The latter wouldpermit heat to be transmitted more quickly from the water into thebuilding. Water 40 having the gelling agent added tends to hold on tostored heat for a longer period of time. A minimal amount of gellingagent is all that is required; too much tends to turn the water 40 intoan opaque mass.

Alternatively, so-called phase-change materials could be used in placeof water. Such materials take advantage of the heat absorbed or releasedby a material when changing from one state to another, such as from asolid to a liquid (melting) or vice versa (freezing) at constanttemperature, and enable a greater amount of heat to be stored in thesolar heating block 20 when the phase-change material is heated througha temperature range which includes the temperature at which thephase-change occurs. Polyethylene glycol, as disclosed in U.S. Pat. No.4,532,917 to Taff et al. noted above, is a phase-change material thatmay be used for this purpose. Many others are known to those of ordinaryskill in the art.

As noted above, the block body 26 generally provides a water thicknessin a range from 3.0 to 6.0 inches. The block body 26 itself may begenerally square, perhaps 8.0 to 12.0 inches on a side, although it neednot be perfectly square. On a practical level, however, the fact thatthe block 20 may become overly heavy and unwieldy if made too large, aswell as generating a large hydrostatic pressure which could more easilyresult in a leak, makes sizes at the smaller end of the stated rangemore preferable.

The inner face 44 of the block body 26 may be clear, frosted orpatterned, as desired, to provide a suitable interior finish. Further,in the view provided in FIG. 2, the top and bottom of the preferredblock body 26 include means by which the solar heating blocks 20 may bestacked upon one another. Specifically, the bottom of the block body 26has feet 46, 47, while the top has a narrowed portion 48 creating volume42 provided for expansion, foot 46 being a continuation of face 34. Feet46, 47, which run the width of the block body 26, straddle the narrowedportion 48 and thereby provide a stable stacking arrangement. Weatherstrip 50 runs between the outer foot 46 of the block body 26 above andthe narrowed portion 48 for the width of the block body 26 and down oneof its two sides—weather strip 50 on its neighbors providing for thebottom and the other of the two sides. Gap 52 between solar heatingblocks 20 on the exterior of the building may be as little as 1/32 inch(0.03125 inch).

FIG. 3 is a horizontal section through another of the solar heatingblocks 20 of panel 10, and partly showing the block 20 immediately toits right, taken as indicated in FIG. 1. Much of the detail shown inFIG. 3 has been described above, and the previously used drawingreference numerals have been inserted where appropriate.

As the top and bottom of the block body 26 includes means by which thesolar heating blocks 20 may be stacked upon one another, so also theleft and right sides of the block body 26, as viewed in FIG. 3, includemeans by which the solar heating blocks 20 may be connected to theirneighbors on the left and right. Referring first to the left-hand sideof block body 26 in FIG. 3, struts 54, 56 extend from the left side ofthe block body 26, strut 54 being a continuation of face 34, and abutagainst the right side of a block body 26 to its left. Between struts54, 56, which run for the full height of the block bodies 26, areinterlock legs 58. As will be seen below, interlock legs 58, of whichthere are two, one above the other, on the left-hand side of the blockbody 26, do not extend for the full height thereof, and do not extend asfar laterally from the left-hand side of the block body 26 as the struts54, 56.

On the right-hand side of the block body 26 is a narrowed portion 60which fits between strut 54 and interlock legs 58 of the block body 26to its right. Narrowed portion 60 includes wedges 62, of which there aretwo, as will be seen below. Wedges 62, which also do not run for thefull height of the block body 26, mate with interlock legs 58 to holdthe block bodies 26 together. Weather strip 50 runs down one side ofblock body 26 between strut 54 and narrowed portion 60.

FIG. 4 is a perspective view of the left side of the solar heating block20. First block body half 28 and second block body half 30 areheat-welded or sealed together along joint 64 to produce a watertightconnection. Weather strip 50 runs along the top of block body 26 alongnarrowed portion 48. Struts 54, 56 extend from the left side of theblock body 26, and continue around the bottom where they become feet 46,47. The surfaces of foot 46 and strut 54 ultimately abut against theweather strips 50 on adjacent solar heating blocks 20 below and to theleft of that illustrated.

Interlock legs 58 extend outwardly one above the other from the leftside of the block body 26. The lower of the two interlock legs 58extends downward like feet 46, 47 to fit between the gap between twosolar heating blocks 20 disposed below, specifically between thenarrowed portions 48 thereof to line the blocks 20 up in a verticaldirection.

FIG. 5 is a perspective view of the right side of the solar heatingblock 20. Weather strip 50 runs, as stated above, along narrowed portion48 on the top of block body 26, and down narrowed portion 60 on theright side of block body 26. Wedges 62 having inclined surfaces 66oriented inwardly toward block body 26 mate with interlock legs 58 of aneighboring solar heating block 20. As such a block 20 is so mated,inclined surfaces 66 bring the two blocks 20 into a tight side-by-siderelationship.

FIG. 6 is an exploded view of the exterior of the left side of the solarheating block 20 as shown in FIG. 4. Lens 32 is shown as being separatedfrom face 34 of block body 26, where it is ordinarily heat-welded orsealed to notch 36. In order to increase the amount of thermal energybeing absorbed by the contents of the block body 26, as an alternativeor in addition to dyeing the water or using a phase-change material, theface 34 may be provided with dots or squares 68, which may cover 50% to80% of the area of face 34.

The squares 68 or, alternatively, dots or figures of some other shape,are arranged in an array on face 34, as shown in FIG. 6. The squares 68are first applied using white or another light-colored paint.Subsequently, the white squares 68 are covered in flat black paint orpaint of some other absorbing color. With the face 34 patterned in thismanner, the black surface of the squares 68 on the outside of the face34 absorbs more heat energy and allows it to be conducted inwardly, towarm the contents of the block body 26. The white or light insidesurface of the squares 68 reflects heat from within the block body 26back therein to reduce heat loss. Between the squares 68, the face 34 isclear or translucent so that some light is able to pass through andprovide natural illumination within the building.

In an alternative embodiment of the solar heating block of the presentinvention, shown in a cross-sectional view in FIG. 7, solar heatingblock 70 has a block body 72 in the form of a glass block. Glass blocksof this type are available in 8″×8″×4″ and 12″×12″×4″ sizes, although a6.0-inch thickness would be more desirable in the present context.

The block body 72 includes a first block body half 74 and a second blockbody half 76 which are produced separately and joined to one another atseam 78. At the top, a hole is drilled for use in filling the block body72 with water 80, or other heat-absorbing material, leaving an air space82 at the top for expansion. A stopper 84 or sealant is then used toclose the hole once the block body 72 is filled.

The inside face 86 of the block body 72 may preferably be frosted orotherwise light-diffusing, while the outside face 88 may be patternedwith an array of squares or other shapes, as described above, tomaximize heat absorption. An outer pane 90 of low-iron glass, preferablyhaving a thickness of 0.125 inches, is attached to the outside face 88using a plastic separator extrusion 92 to minimize heat loss outwardfrom the glass block body 72, and to create a volume, preferably havinga thickness of 1.0 inches, for a translucent insulating material 94,such as an aerogel material, as described above. The plastic separatorextrusion 92 is sealed to the block body 72 and outer pane 90. The1.0-inch thickness of aerogel provides an R-value of 8.0, offering ahigh resistance to heat flow from within the block body 72.

The glass block body 72 and pane 90 represent an attempt to make a moredurable solar heating block 70 than that previously described. However,the glass solar heating block 70 may have to be deployed differentlythan is currently the case, because mortar used to cement the blocks 70to one another may provide a path, also known as a “thermal short”, forheat to escape outwardly from within the block 70. In order to avoidsuch an outcome, individual solar heating blocks 70 may have to beseparated from one another by plastic strips, and grouting or mortar mayhave to be used only where it is not able to conduct heat from the blockbody 72 to the exterior of the building.

In still another alternative embodiment of the solar heating block ofthe present invention, shown in a cross-sectional view in FIG. 8, solarheating block 100 has a block body 102 which includes three sections,namely, a first interior block body half 104, a second interior blockbody half 106, and an inner lens 108, the latter being so-called becauseit is inside a building when solar heating block 100 is in use asintended. The first interior block body half 104 and the second interiorblock body half 106 are bonded to one another along joint 110, and theinner lens 108 is bonded to the second interior block body half 106along joint 112.

The first interior block body half 104, the second interior block bodyhalf 106, and the inner lens 108 are molded from clear or translucentplastic, such as an acrylic plastic, and heat-welded or sealed alongjoints 110, 112 to produce watertight connections. Water 114, or otherheat absorbing material, fills the interior of the block body 102, thatis say, filling the volume between the first interior block body half104 and the second interior block body half 106, except for an air space116 at the top allowing for expansion, as well as the volume between thesecond interior block body half 106 and the inner lens 108. The water114, or other heat-absorbing material, is introduced through hole 118,which is subsequently closed with a plug 120 and a wedge 122, whichlastly is inserted into the center of plug 20 and forced thereinto toensure that the plug 120 makes an airtight seal in hole 118.

It will be observed that the block body 102 has an internal wall 124,which is physically part of the second interior block body half 106 andwhich separates the two compartments formed by the first interior blockbody half 104 and the second interior block body half 106 and by thesecond interior block body half 106 and the inner lens 108. Internalwall 124 includes holes 126 so that water 114, or other heat-absorbingmaterial, will pass into the compartment between the second interiorblock body half 106 and the inner lens 108 when introduced through hole118 and will completely fill that compartment, leaving no air trappedtherewithin.

Internal wall 124 is preferably frosted, ensuring that it is translucentrather than transparent, for reasons to be explained more fully below.Alternatively, a diffuser plate 128 of frosted glass or plastic, maydisposed adjacent to internal wall 124 within the compartment formedbetween the first interior block body half 104 and the second interiorblock body half 106 for the same purpose. As above, inner lens 108 maybe clear, frosted or patterned, as desired, to provide a suitableinterior finish.

A heat-absorbing grid 130 is disposed adjacent to outer wall 132 offirst interior block body half 104 and within the water-filledcompartment formed between the first interior block body half 104 andthe second interior block body half 106. Alternatively, and preferably,the heat-absorbing grid 130 is disposed adjacent to, or is physicallyjoined to or is combined with, diffuser plate 128. Heat-absorbing grid130 has the same purpose as squares 68 described above, that is, itincreases the amount of thermal energy being absorbed by the contents ofthe block body 102. In the present embodiment, the heat-absorbing grid130 is a perforated plate which is black on one side and white, or someother light color, on the other side. The perforations take up from 20%to 50% of the area of the heat-absorbing grid 130 so that the area notrepresented by the perforations is from 50% to 80% of the total areathereof. As before, the heat-absorbing grid is oriented so that theblack side faces outwardly toward the exterior of the building whensolar heating block 100 is in use, while the white or light side facesinwardly toward the interior of the building.

On the left-hand side of the solar heating block 100 in FIG. 8, whichwill be the side of the block 100 on the outside of the building is anouter lens 134, which is also molded from clear or translucent plastic,such as an acrylic plastic or other material having high solartransmission. The outer lens 134 is heat-welded or sealed to firstinterior block body half 104 at joint 136. Translucent insulatingmaterial 138 is disposed in the volume between the outer lens 134 andouter wall 132 of first interior block body half 104. Preferably, thetranslucent insulating material 138 is an aerogel material, as describedabove.

FIG. 9 is a cross-sectional view taken through two vertically stackedsolar heating blocks 100, as they would be used in a solar heating panel10. Between the vertically stacked solar heating blocks 100 is a bar140, preferably of steel, which runs from one side of frame 22 to theother to provide the solar heating panel with additional strength andstability. Bar 140 may have cross-sectional dimensions of 0.125 inch by1.5 inch. However, as will be realized by one of ordinary skill in theart, bars 140 would tend to be apparent to an observer viewing the solarheating panel from within a building as dark lines running horizontallyacross the solar heating panel 10. This effect is minimized orcompletely eliminated by the diffuser plates 128 in the verticallystacked solar heating blocks 100. The diffuser plates 128 scatter lightpassing through the solar heating blocks 100 from left to right in FIG.9, that is, from outside to inside the building, in all directions. Inthis manner, light is scattered around the opaque bar 140 making thepresence of the bar 140 less apparent to an observer in the building. Itshould also be noted that air space 116 is hidden from the view of anobserver on either side of the stacked solar heating blocks 100.

Gaskets 142 separate the outer lenses 134 and the inner lenses 108 ofadjacent solar heating blocks 100 to prevent thermal shorts and toeliminate drafts which would compromise the functioning of the solarheating panel 10 comprising solar heating blocks 100.

FIG. 10 is perspective view of the tops of two adjacent solar heatingblocks 100 showing their connections to one another for additionalsupport and stability. The sides of the first interior block body half104 and the second interior block body half 106 have vertically orientedspacing ribs 144 to provide a slight gap 146 between laterally adjacentblocks 100. On each side of the blocks 100 is a slot 148, those on theadjacent blocks 100 lining up with one another to produce a generallyU-shaped combined slot. Connector 150, adapted to fit into the combinedslot and having inclined surfaces, draws the blocks 100 into a tightrelationship as it is forced down into the combined slots 148. Bar 140fits between the two connectors, 150, and the next horizontal row ofsolar heating blocks sit on top of the connectors 150 below.

FIG. 11 is a perspective view of the tops of two adjacent solar heatingblocks 100 showing an alternate approach for connecting them to oneanother. In this alternate approach, the connectors are generallyH-shaped having vertical legs which gradually narrow from the horizontalcross member to their tops and bottoms. Again, on each side of theblocks 100 is a slot 152, those on adjacent blocks 100 lining up withone another. As show in FIG. 11, the connectors 154 have horizontalcross members 156 which maintain a desired separation between adjacentsolar heating blocks, although vertically oriented spacing ribs may alsobe present. The legs 158 of the connectors 154 are inserted into slots152 and draw the adjacent solar heating blocks 100 into a tight lateralrelationship with one another. As above, connectors 154 straddle bar140, and the next horizontal row of solar heating blocks 100, which haveslots 152 on their undersides, sit on top of the connectors 154 below.

In general, the solar heating blocks of the present invention provideday lighting to the interior of a building in which they are used and,as such, it may be desirable to use them as east-, west- andnorth-facing (or south-facing in the southern hemisphere) windows aswell as in the south-facing walls (in the northern hemisphere) for whichthey are primarily designed. Their use in east- or west-facing walls,however, will lead to overheating in summer, as they would receive thedirect summer sun. However, with an array of white squares used insteadof the black ones described above, most of the thermal radiation will bereflected back outside without passing through the solar heating block.This will permit the same day lighting to be achieved as in thepreviously described south-facing system without overheating. Moresophisticated solar reflection systems may alternatively be used insteadof the white squares described above.

Winter solar heat gain would not be required in east-, west- andnorth-facing walls. As a consequence, a less sophisticated translucentinsulation material than aerogel, such as white fiberglass or fumedsilica, could be used in solar heating blocks for those walls.

For example, and referring to the embodiment shown in FIG. 8,south-facing walls (or north-facing walls in the southern hemisphere)would include the solar heating block 100 as described above. For east-and west-facing walls, holes 126 would not be provided so that aerogelmaterial could be disposed between both the outer lens 134 and the firstinterior block body half 104 and the second interior block body half 106and inner lens 108. Water, or other heat-absorbing material, would thenfill only the compartment between the first interior block body half 104and the second interior block body half 106. Heat could than be storedin that interior compartment and subsequently vented to the outside ofthe building, perhaps with the assistance of a temperature-controlledfan to pass air through the spaces between adjacent blocks.

For north-facing walls (dr south-facing walls in the southernhemisphere), the water would be omitted from the compartment between thefirst interior block body half 104 and the second interior block bodyhalf 106, leaving this compartment empty. Alternatively, thiscompartment, too, could also be filled with aerogel material.

One problem with aerogel material, however, is its tendency to settleover the course of time in response to vibrations and other movements,as aerogel tends to settle as its constituent pellets achieve idealpacking. For this reason, it is not currently used between sealed glassinsulating panels, because settling would leave a large gap at the topof the panel. In the present invention, the relatively small height ofthe solar heating blocks reduces the scale of the settling and permitsit to be hidden or otherwise addressed more simply.

Referring now to FIG. 12, a cross-sectional view through a solar heatingblock 200 taken in the same manner as shown in FIG. 2, specifically,taken in a vertical direction and looking toward the right side of thepanel as illustrated in FIG. 1. In solar heating block 200, lens 202 issealed to the outer face 204 of the block body 206. Translucentinsulating material 208 may settle as indicated by the presence of space210 at the top of the volume between the lens 202 and outer face 204 ofblock body 206. As before, the outer face 204 may be patterned with anarray of heat-absorbing squares as previously described.

It will be noted that the upper and lower surfaces of lens 202 areinclined in a downward direction. As a consequence, space 210, fromwhich translucent insulating material 208 has settled, is hidden fromview by the lens 202 of the solar heating block 200 immediately above.At the same time, air space 212 at the top of block body 206 is alsohidden from view.

The same approach may also be used on the inside of the solar heatingblock 200. Block body 206 may comprise a first block body half 214 and asecond block body half 216, which may be physically identical to lens202. First block body half 214 and second block body half 216 may behermetically welded or sealed to one another along seal 218. Secondblock body half 216, like lens 202, has upper and lower surfaces whichare inclined in a downward direction. As a consequence, the air space212 is hidden from view by the second block body half 216 of the solarheating block 200 immediately above. Weather strip 220 may be used asshown between the lenses 202 and second block body halves 216 of thevertically stacked solar heating blocks 200.

FIG. 13 is a cross-sectional view through solar heating block 200 takenin the same manner as shown in FIG. 3, specifically, taken in ahorizontal direction and looking downward in the panel as illustrated inFIG. 1. Referring to FIG. 13, solar heating block 200 interlocks withthose on its left and right in a manner similar to that shown in FIG. 3.Specifically, a pair of interlock legs 222 are on one side of block body206 while a pair of wedges 224, similar to those previously describedabove, interlock with one another to hold solar heating block 200securely to its neighbors on either side. At the bottom of the blockbody 206, interlock legs 222 extend downward into the space between theneighboring blocks 200 below to align the blocks 200 vertically.

In an alternative approach, a honeycomb material 230, shown in aperspective view in FIG. 14, of appropriate dimensions may be disposedbetween lens 32 and face 34 of block body 26, such that the individualcells 232 are oriented in a horizontal direction. The honeycomb material230 may, for example, be of a clear Mylar, and may be placed in lens 32with the individual cells 232 oriented in a vertical direction.Translucent insulating material 234, such as aerogel, may then be pouredinto cells 232 to completely fill them. After the translucent insulatingmaterial 234 is leveled, and the block body 26 attached to the lens 32,any settling of the translucent insulating material 234 within theindividual cells 232 will be far less noticeable than it would have beenwithout the honeycomb material 230.

In yet another approach, shown in vertical cross section in FIG. 15, asolar heating block 240 includes an absorber plate 242 having an arrayof absorbing squares as described above. Between the absorber plate 242and the outside of the solar heating block 240 is translucent insulatingmaterial 244, such as aerogel. On the inside of the absorber plate 242,the liquid contents which absorb heat are sealed within a plastic bag246, or the like, which maintains pressure on the absorber plate 242.Any settling of the translucent insulating material 244 is rendered lessapparent by the pressure on absorber plate 242 causing the translucentinsulating material 244 to continue to fill the space between theabsorber plate 242 and the outside of the solar heating block 240. Theinside of the solar heating block 240 includes limit stops 248 whichlimit the extent the absorber plate 242 may move toward the outside ofthe block 240. The block 240 may also be open at vent 250 to allow forexpansion. In addition, the absorber plate 242 may be eliminated and theabsorbent array of squares printed directly on plastic bag 246 in analternative arrangement. Solar heating block 240 may, in thisembodiment, be a clear plastic (acrylic) block.

In still another approach, shown in vertical cross section in FIG. 16,solar heating block 256 includes a separate, interior liquid container258, which may be blow-molded, filled with liquid and sealed, leavingair space 260 for expansion. Outer face 262 of liquid container 258 maybe provided with an array of absorbent squares, as previously described.

On the outside of the liquid container 258 is translucent insulatingmaterial 264, such as aerogel, occupying the space between the liquidcontainer 258 and the outside of the solar heating block 256. On theother side of the liquid container 258 within the solar heating block256 is an air space 266 which has some insulating value to slow thetransfer of heat from the contents of the liquid container 258 to theinterior of the building. Springs 268 bias the liquid container 258toward the translucent insulating material 264 to negate any settlingwhich may take place therein. The inside face 270 of the solar heatingblock 256 may be of a light-diffusing character, for example, frosted.

Finally, the embodiment shown in FIG. 8 enables still another approachtoward solving the settling problem to be taken. Referring to FIG. 17, across-sectional view of first interior block body half 104 and outerlens 134 before they are joined to one another, it will be noted thatouter wall 132 of first interior block body half 104 protrudes beyondedges 160, which are heat-welded or sealed to edges 162 of outer lens134 to produce joint 162 of outer lens 134 to produce joint 136. Theamount of protrusion is labeled “X” in FIG. 17.

Translucent insulating material 138, such as an aerogel material, isdisposed in outer lens 134 to a depth an amount “Y” below edges 162. Byfilling the outer lens 134 to a depth such that “Y” is less than “X”,the translucent insulating material 138 is compressed by outer wall 132to some degree when the first interior block body half 104 is forceddown thereonto to bring edges 160 into contact with edges 162 to permitjoint 136 to be formed. The result is shown in FIG. 18, where thetranslucent insulating material 138 occupies the entire volume betweenthe first interior block body half 104 and the outer lens 134.

The compression of the translucent insulating material 138 has beenfound to cure the settling problem by packing it into the availablevolume. In the compressed state each particle of the translucentinsulating material 138 becomes locked into position relative to othersto prevent settling from occurring. It has been found that an amount ofcompression, which equals “X-Y”, equal to about 20% of the originaluncompressed depth of the translucent insulating material 138 in theouter lens 134 solves the settling problem completely.

Returning, now, to the view presented in FIG. 1, it may be desirable toinstall insulating fabric tiles on the inside surfaces of the solarheating blocks 20 shown. Such fabric tiles may be useful to moderate therate at which solar heating blocks 20 release stored heat into the room,as well as to provide an aesthetic visual appearance and to allowconsumers to coordinate the appearance of the entire solar heating panel10 with the rest of the room. A felt insulating pad, light-transmitting,and having desired thicknesses and numbers of layers, can be trapped bythe fabric tile to provide varying degrees of insulation to temper thesystem to achieve a desired R value, such as R-1 to R-3. A higher Rvalue on the inside, while still not approaching R-8 of aerogelmaterial, still allows a majority of the stored heat to flow towards theroom, but tempers its flow and allows the temperature of water in theblocks 20 to remain hotter and to heat the room for a longer period oftime.

FIG. 19 is a perspective view of a portion of the solar heating panel 10shown in FIG. 1 showing the installation of a fabric tile 280 on one ofthe solar heating blocks 20. Trim 282, which may be of wood or plastic,snaps into the gaps between adjacent solar heating blocks 20 to hold thefabric tile 280 in place. The optional translucent felt insulating pad284, when desired, is installed behind the fabric tile 280.

In an alternate embodiment, shown in FIGS. 20A and 20B, fabric tile 286has the flattened appearance shown in the plan view of FIG. 20A withcreases 288. When folded along the creases 288, the fabric tile 286 isinstalled in the gaps between adjacent solar heating blocks 20, as shownin side view in FIG. 208. The optional translucent felt insulating pad290, when desired, is installed behind the fabric tile 286.

It should be appreciated that a framed window consisting of multipleblocks may use blocks having different degrees of translucency and heatabsorption. These blocks could include a transparent block filled withwater using an air space as insulation, a transparent or translucentblock filled with water using aerogel as an insulation, and atransparent or opaque block filled with phase-change material usingaerogel as insulation, or any combination thereof. This provides forprivacy with some see-through and balances the energy differencesbetween an air-insulated transparent water block and anaerogel-insulated semi-opaque phase-change block, thus creating a windowsystem which, as a whole, is very energy efficient.

Modifications to the above would be obvious to those of ordinary skillin the art, but would not bring the invention so modified beyond thescope of the appended claims.

What is claimed is:
 1. A solar heating block for covering at least aportion of a building wall opening, comprising: a stackablesubstantially rectangular parallelepiped shape, containing both a lenscompartment in a block front portion, which is filled with an insulatingmaterial, and a heat absorbing compartment in a block rear portion,wherein the block is substantially clear or translucent in a front toback direction; and a narrow expansion volume portion in a block topportion, extending away from a block bottom portion and disposed abovethe heat absorbing compartment; wherein the narrow expansion volumeportion is hidden from view, when plural blocks are vertically stacked,within an inwardly contoured portion disposed in the block bottomportion.
 2. The solar heating block of claim 1, wherein the contouredportion is defined by a pair of feet running across the bottom of theblock.
 3. The solar heating block of claim 1, wherein the contouredportion is an indented portion in the block bottom portion.